I mentioned that the supplement chondroitin, well known for apparent relief to joints and especially to knees, was known to be risky for prostate cancer patients in the new thread on exercise, and kcon asked about that. Here is an excerpt of his post. I decided there should be a new thread just about chondroitin as I was disturbed by the details I learned. This stuff looks downright dangerous
to prostate cancer patients (and to men generally because they might become prostate cancer patients)! Quote:
Originally Posted by kcon
Second, I wanted to inquire about your comment on chondroitin (your next-to-last paragraph). I had knee reconstruction--twice on the same knee over 25 years ago--and am very arthritic there. (I can run forever on an elliptical tranier, but can't run 50 yards on my own without straining my knee/joint.) I've been taking the combination glucosamine chondroitin for nearly 10 years, and it definately has reduced pain. Can you add anything to your comment "I avoid the combo with chondroitin as there is evidence that is not good for prostate cancer patients"?
So many of these research findings have to do with odds, and I suspected the one about chondroitin was one of them. As with so many things about prostate cancer where there are benefits on the one hand but risks on the other, taking chondroitin seemed like one of those judgement calls we all have to make individually, and it's more complicated when we personally are getting benefit from a supplement that has some risk: here, I was supposing, we probably have to decide whether the benefit to our knees is worth whatever risk there is.
I had not looked into the research basis for avoiding chondroitin before today, but after a small amount of time spent checking, my personal conclusion is that chondroitin is too risky for prostate cancer to justify any benefit!
I was really taken aback by the strength of the evidence!
The evidence has cleared glucosamine, so possibly switching to just that supplement would give enough relief.
As with so many of these kinds of questions, it helps to go to www.pubmed.gov
, a site we can use here because it is Government sponsored. I did a search for " prostate cancer AND chondroitin " and got 21 hits; after seeing some rat studies, I put on limits for only studies done in humans that had abstracts, getting 16 hits. I took a look at a few of the abstracts by clicking on the blue hypertext. I'm fairly used to reading this stuff, but this group of hits looked extra technical. Try PubMed yourself and just ignore the highly technical stuff. Anyway, here are my excerpts and bracketed comments for a few of the clearer comments:
From the first hit of the 16, first author Sakko, 2008: "... The glycosaminoglycan chondroitin sulfate is significantly increased in the peritumoral stroma of prostate tumors compared with normal stroma and is an independent predictor of prostate-specific antigen (PSA) relapse following radical prostatectomy. ..."
Hit 2, from first author Teng, 2008: "... Non-sulfated chondroitin expression ... in adenocarcinoma ...correlated significantly with ...unfavorable outcome, including higher pathological T stage and Gleason score, presence of tumor in both prostatic lobes, extraprostatic extension, seminal vesicle involvement and preoperative prostate-specific antigen levels. These data suggest that non-sulfated chondroitin is a potentially useful biomarker for prostate cancer, and may be involved in regulating prostate cancer behavior."
Hit 8, first author Glynne-Jones, 2001: "... Studies ... demonstrate that TENB2 is a chondroitin sulphate proteoglycan. ... These data are indicative of a significant role for TENB2 in the progression of poorly differentiated tumour types, with implications for prostate cancer detection, prognosis and therapy."
Hit 9, first author Ricciardelli, 1999 (and full paper available free via www.pubmed.gov:
"... Chondroitin sulfate (CS) ... is a candidate biomarker as elevated levels of CS in peritumoral stroma of prostate cancer have been associated with prostate-specific antigen (PSA) failure. ... CS level, Gleason score, and preoperative serum PSA levels were independent predictors of PSA failure.... Patients with low CS levels had significantly fewer PSA failures after radical prostatectomy than patients with high levels of CS [basically 32% failures if CS level was less than 7 versus 50% failure if greater than 7].... In the subgroup of patients with preoperative serum PSA levels < 10 ng/ml, CS was particularly useful in discriminating retrospectively those patients most suited for surgery [basically, 14% failure if CS less than 7 versus 47% failure if CS equal to or greater than 7, with an extremely high degree of statistical confidence; WOW! - did not know that!
] ... We conclude that measurements of CS level can assist in predicting patient outcome after surgery. Additionally, our data suggest that the combination of CS and PSA measurements may improve outcome prediction for patients with intermediate Gleason scores."
I'm really impressed with that last study and a little surprised that testing for chondroitin sulfate has not caught on. There is probably a reason, but I would like to know what it is.
Some of the other hits looked interesting too, but this sure reinforces my decision to stay away from chondroitin! Of course I'm not an MD and have had no enrolled medical education, but if I had a stock of chondroitin or chondroitin mixed with glucosamine, I would go straight to the cabinet and chuck it in the trash! (Or my wife could use it; I don't recall hearing that it is a problem for women.)
It is disturbing that supplement sellers do not highlight a warning about the chondroitin-prostate cancer connection, especially considering that prostate cancer is so common.
In my opinion, there should be a prominent caution. I just checked the brand my wife uses. It's from CVS, and there is a fine black print caution to consult a doctor before using the supplement if you are taking any medication, which would apply to many of us. Well, that's pretty broad and bland; it reads like the typical stuff that consumers don't pay attention to. I would like to see a warning in large red letters!